U.S. Pat. No. 7,077,810 discloses a method for predicting an onset of clinical episode, the method including sensing breathing of a subject, determining at least one breathing pattern of the subject responsively to the sensed breathing, comparing the breathing pattern with a baseline breathing pattern and predicting the onset of the clinical episode at least in part responsively to the comparison. Predicting the onset of the clinical episode may not be reliable and there could be variations in diagnosing asthma.